This invention relates to a material spreader and, more particularly, to a material spreader of the rotary type used for broadcasting fertilizers, seeds, or other material in particulate form onto the ground or turf.
Two types of material spreaders are in widespread use today. One type is a drop spreader in which the material is discharged by gravity in a pattern whose dimensions conform to those of the discharge openings of the spreader. The second type is a rotary spreader in which the material is cast beyond the spreader to cover an area much wider than the dimensions of the spreader.
Drop spreaders, as is well known, produce a controlled distribution pattern. Rotary spreaders do not produce a controlled distribution pattern; however, they offer the advantage of speed of application, due to their wide swath of distribution. With rotary spreaders, feathering of the particulate material occurs at the edges of the distribution pattern. The feathering or progressively less dense distribution of particulate material as the pattern extends from the spreader permits overlap between successive swaths of distribution and thus a certain amount of error in spreader location can occur without a streaking problem which frequently occurs with drop spreaders.
Rotary spreaders push more easily than drop spreaders and are better suited to the use of corrosion resistant materials. Rotary spreaders also have the advantage of using only a few large exit ports from the material hopper for distribution of the particulate material rather than a series of small ports, thus accommodating larger particle sizes.
Rotary spreaders have one disadvantage that is well known. Specifically, if the spreader is used adjacent a driveway, sidewalk or the like, the particulate material being spread may be dispersed onto the sidewalk, or driveway. As a result, material is wasted unnecessarily. Also, it is difficult with a rotary spreader to prevent the material being broadcast from coming into contact with vegetation which is adjacent the area which is to receive the material. This problem has been solved in two ways. On rotary spreaders which have plural valved openings through which material drops from the hopper onto the rotary disc/impeller, it has been proposed to close one of the openings and thereby restrict distribution of material to an area of the impeller. The thought is that the impeller will then throw the material to only one side of the spreader. This has not been an effective solution. Also, rotary spreaders have been provided with deflectors which are movable into the path of the material being spread and intercept the material so that the material will not be distributed onto the sidewalk, driveway, vegetation or the like. Such deflectors, however, have had a major disadvantage of causing the material which is intercepted to form in a concentrated manner on the turf with adverse effects on the turf, such as burning if fertilizer is being distributed.
The present invention is specifically directed to a deflector for use on rotary-type spreaders. The deflector of the present invention is constructed so that the material may be accurately broadcast in a pattern without being deposited, for example, on a driveway, sidewalk, etc. and without an excessive deposit of material in any particular area. In fact, the deflector of the present invention intercepts material being broadcast by the rotary disc and causes the material to be broadcast in a pattern having a straight line along one side of the spreader and causes material that would have been broadcast beyond that line to be broadcast on the turf in front of the spreader and to the side of the spreader opposite the side where the deflector is located.
Specifically, the deflector of the present invention is movable into a position radially adjacent the rotatable disc of the rotary spreader. The deflector has a surface which curves around the rotatable disc and also has a nose portion which directs the material at a relatively high velocity across the front of the spreader and to the side of the spreader opposite the side where the deflector is mounted. The deflector, of course, prevents the material from being spread in a direction laterally to the side of the spreader on which the deflector is mounted. The deflector directs the material at a relatively high velocity across the front of the spreader and to the opposite side of the spreader. Certain structural features of the deflector contribute to the high velocity spreading of the material. These include (1) the angle of the forward or nose portion of the deflector relative to the base portion thereof and/or the angle of the nose portion relative to the direction of spreader movement, and (2) the curved internal surface of the deflector against which the particles being spread impinge.
The deflector of the present invention is movable vertically from a position located above the rotary distributor disc to a position radially adjacent the disc. When the deflector is located in a position above the rotary disc, it does not deflect or change the direction of the material which is broadcast by the disc, and therefore the spreader operates in a conventional fashion as any rotary spreader distributing particulate material to the opposite sides of the spreader. When the deflector is moved downwardly into a position radially adjacent the disc, the material which is distributed to the one side of the spreader is intercepted by the deflector and its direction of distribution is changed by the deflector. Specifically, the material impinges the interior surface of the deflector. The material rebounds from the surface and is directed through the forward nose portion of the deflector. The velocity of the material as it rebounds from the surface is sufficient to cause the material to be broadcast to the side of the spreader a substantial distance opposite the side where the deflector is mounted.